Electric translating-device for musical instruments



Y, 3936 A E -n fiz fi fl ELECTRIC TRANSLATING DEVICE FOR MUSICAL INSTRUMENTS Filed June 5, 1955 2 Sheets-Sheet l FIG; I.

INVENTOR v M M A. LESTi Jan. 7, 1936.

ELECTRIC TRANSLATING DEVICE FOR MUSICAL IHSTRUEENTS Filed June 5, 1935 2 Sheets-Sheet 2 EWENTOR M M Patented Jan. 7, 1936 UNITE-D STATES nrnc'rmo 'rnansmrmc nnvrcn FOB; MUSICAL INSTRUMENT Arnold 1mm Angela? can. Application June 5, 1935, Serial No.;25,100

14 Claims.

My invention relates to an electricaltranslating device for use with musical instruments which are not sufficiently loud when played in the normal manner. This device translates the musical vibrations into corresponding electrical values and these are electrically amplified and then translated into corresponding sounds by a loud speaker. to steel the guitar. 7

An important object of my invention is to provide an adequate electrical translating device which is sufilciently small in size so that it may be easily attached to the most effective part of the musical instrument or easily detached from the same. e

A further object of my invention is to provide an adequate translating device which will faithfully reproduce the musical tones of the instrument and not extraneous mechanical vibrations which may exist in the body of the instrument when it is played. I have found that this feature is met by a translating device utilizing solenoid means to produce electrical currents caused by the vibrations of the steel strings of the musical instrument; the said strings being permanently magnetized beforehand adjacent to the solenoidal pick-up device. In this connection, a further detailed object of my invention is to provide means of changing the relative intensities of the bass and treble notes by moving the above mentioned solenoidal device into proper relation with the magnetized portions of the steel strings.

Another important object of my invention is to provide, along with the above mentioned features, a translating device which is free from pick-up action engendered by extraneouselectrical and magnetic influences. These last mentioned influences are found to produce extremely objectionable noises. In the construction of my invention I have found that two or more'solenoids may operate together so that each neutralizes. the effects of the other insofar as extraneous unwanted magnetic influences are concerned, but that their positions with respect to the vibrating magnetic portions of the musical instrument, causes an addition or summation of their respective translating currents.

A further. detailed object of my invention is to provide means for properly magnetizing the steel vibrating members of the musical instrument in a manner which will produce maximum effects.

With the foregoing and other objects in view, which will-be made manifest in the following The invention is particularly adapted; stringed musical instruments such as a REISSUED' detailed description, and more particularly in the annexed claims, reference is had to the attached drawings for an illustrative embodiment of the inventionwherein,

Fig. 1 is a plan view of aguitar with my in- I vention applied thereto.

Fig. 2 is a side view thereof; Fig. 3 is a plan view of the translating device with top cover removed.

Fig. 4 is a sectional view through the line 4-4 m of-Fig. 3, andshowing also how :the device is held to the instrument at the sound hole.

Fig. 5 is a'sectional-view thrbug'h the line 5-5 of Fig. 3. I

Fig. 6 is a plan view of the translating device showing an alternative method of fastening the same to instruments without sound holes.

Fig. 7 is a diagrammatic view of the invention illustrating four coils and cores, the method of magnetizing the steel strings, and the lines of magnetic force during the process of magnetization.

Fig. 8 is a diagrammatic view of the invention somewhat similar to Fig. 7, but showing the magnetic lines of iorce surrounding the steel string after magnetization, an interfering stray field,

an amplifier and loud speaker.

Fig. 9 is a diagrammatic view showing the translating device with two coils and cores, the

lines of magnetic force surrounding the steel 80 string after magnetization, an interfering stray field, a switch held in the playing position, an amplifier and loud speaker. I Referring to the drawings wherein similar characters represent similar parts throughout, l is the body of a guitar and 2 the fingering board. Characterv 3 represents the sound hole at which is held the translating device designated generally by I. 1 represents generally the steel strings which are vibrated during the act of 40 playing. Translating device 6 is held to the guitar by spring 24. The small spring 8 around the cable 9, where it enters the translating device 6, safeguards '9 from excessive wear at that point. In Fig. 3 the coils I0 and H, having iron cores #2 and I3, are shown'connected to insulated leads l4 and I! and their center connection l6 being connected to the case I1, made 01' magnetic material. A shielding 18 around leads I and I5 constitutes a return lead, also connected to the case II. The windings in coils Ill and II are in opposite directions, as can be seen from the direction of the ends I9, 20, 2|, 22. The case l1, made of magnetic material, aids in the pick-up action by reducing the magnetic re- 16, 11, leading to a source of potential to produce field excitation.

In the playing position shown in Fig. 9, if the steel string 1 vibrates, the surrounding magnetic field 18, 19 will also vibrate inducing currents in the coils 58, 59, while being insensitive to the stray field 80, as above mentioned. The currents are applied to the input 68, 69, ll, of the amplifier 61, which amplifies them, and from the output 8], 82,

of the amplifier they are connected to the loud speaker 15, which translates the amplified currents into sounds.

Various changes may be made in my invention, by those skilled in the art, without departing from the spirit thereof as set forth in the drawings, specification and claims.

I claim:

l. The combination, in steel stringed musical instruments, of a plurality of wire coils, iron cores contained within the said coils each having a face of equal distance to the strings, means for sending a direct current through the coils to produce a series of magnetized zones, in each steel string, with reversed magnetic polarity for adjacent zones whereby induced currents are established in the coils when the strings are vibrated, means for disconnecting the direct current, means for amplifying the induced currents and or translating them into sounds.

2. The combination, in steel stringed musical instruments of a plurality of wire coils spaced in consecutive order and each having iron cores, means for sending a direct current through the coils to produce magnetic fields of opposite polarity in adjacentcoils and magnetizing the strings therewith, whereby induced currents are established in the coils when the strings are vibrating.

3. The combination, in steel stringed musical instruments, of a plurality of insulated wire coils each having iron cores, a case made of magnetic material having an open top and a closed bottom and containing the wire coils within, bent sides on the case to hold a non-magnetic top cover, a spring having two free ends and a midsection fastened to the outer bottom of the case and adapted to hold the same to the musical instru-.

ment at the sound hole, means for utilizing the said wire coils to produce a series of magnetized zones in each string whereby currents are induced in the coils when the strings are vibrating, an amplifier to increase the amplitude of the currents and a loud speaker to translate the amplified currents into sounds.

4. The combination, in steel stringed musical instruments, of two solenoids each adapted to produce electrical currents from the influence oi. vibrating magnetic fields, means for sending a direct current through the solenoids to magnetize adjacent portions of the steel strings in opposite magnetic polarity whereby strong electrical currents are produced from the cumulative eflects of the solenoids when these currents are induced from the vibrations of the magnetized strings but minimizing the efiects of stray magnetic fields from the neutralizing eflects of the solenoids, an amplifier to amplify the currents and a loud speaker to translate the amplified currents into sounds;

5. The combination, in steel stringed musical containing the solenoids within, means for sending a direct current through the solenoids to produce a series of magnetized genes in each steel string with'opposite magnetic polarity for adjacent zones whereby strong vibrating currents 5 are induced in the solenoids from their cumulative effects when the strings are vibrating, but minimizing the influence of stray magnetic fields, means for disconnecting the direct current, an amplifier to increase the amplitude 01' the vibrat- 1) ing currents, and a loud speaker to translate the amplifiedcurrents into sounds.

6. The combination, in steel stringed musical instruments, of a plurality of an even number of insulated wire coils having cores made of mag- 15 netic material, a case also made of magnetic material having an open top and a closed bottom and containing the wire coils within, means for fastening the case to the musicalinstrument below the strings with the topside facing the 20 strings, a source of direct current, a switch to connect the coils to the source of direct current to produce a series of magnetic zones in each steel string whereby, when the strings vibrate, currents are induced in the coils and reinforced by their cumulative action while neutralizing stray magnetic influences, means on the said switch to disconnect the coils'from the source of direct current and to connect the same to an amplifier to amplify the currents, and a loud speaker to S0 translate the amplified currents into sounds.

7. Hie-combination, with steel stringed musical instruments, oil a series of insulated wire coils spaced in consecutive order and each having iron cores with faces equidistant to each steel 3 string, an amplifier having triodes grid input, a source of direct current, a switch having a first position to connect the direct currentto the wire coils andsimultaneously shunt the triodes grid input producing a series of magnetized zones in 40 each steel string, a second position of the switch to disconnect the first position connections, and simultaneously connect the wire coils to the triodes grid input thereby sending vibrating currents, induced in the coils when the strings are 45 vibrated, through the amplifier which boosts the same, and a loud speaker to translate the boosted currents into sounds.

8. The method of electrically increasing the volume of steel stringed musical instruments, 50 which consists in utilizing a plurality of electromagnets to magnetize steel strings into magnetic zones of opposing polarity for adjacent zones, utilizing the same coils to produce electrical currents when the strings are vibrated, amplifying 55 the said currents and translating them into sounds.

9. The method of reducing noise when electrically amplifying the volume of steel stringed musical instruments which consists in utilizing a to series or wire coils with adjacent coils connected in opposite polarity. utilizing the coils to magnetize portions of the steel strings into magnetic zones, and utilizing the same coils toproduce currents when the strings are vibrated.

10. The method 0! adjusting the relative intensities of the bass and treble notes when electrically amplifying the sounds of steel stringed musical instruments which consists in utilizing a series of coils tomagnetize portions or the steel 70 strings, adjusting the relative positions of the coils with respect to the magnetic portions to obtain the desired relative intensities, and utilizare vibrated.

' the strings are vibrated.

12. The combinetion in. steel stringed nice! 1 instruments, of a pity of wire coils each spaced consecutively, cores contained Within. each coil each having a face substantially equidistant to each steel string and adapted to "eneach steel string ,into a series of magnetic zones of reversed polarity for adjacent zones end corresponding to the polarity or the coils when the said coils are momentarily energized by e direct current whereby currents ere established in the coils when the strings are vibrated;

13. The combination, in steel stringed musical instruments, or a. plurality of electromegnets,

means for sending e momentary direct-current its the and elect snets to eechsteel string into eticeones of reversed polarity for odjscent zones whereby cumulative currents are induced in the eiectrognets when the strings we vibrated.

. I 5 14. The .comhition, in steel'strihsed musicsl insents of a plurality of wire coils consecutively on one side of the steel strings.

- cores contained within the coils eech hevins'e fece substsntielly of equal distance to each steell string, e case rm e02 etic material having en omn top'end a, closed bottom and conng the coils within, bent sides on the case to hold a.

non-meti'c top coven'e spring hsving two free ends and s mid-section fastened to the outer bottom of the case and adopted to hold the same to the musics] instrument, and means for sending s momentary direct current through the coils to metize each steel string whereby currents 20 are induced in the coils when the strings are vibrated. ARNOLD LESTI. 

